Dreams are one way the unconscious mind has of communicating with the conscious mind. I look at it as the brain trying to decipher previously received information (images, emotional displays, words, et cetera). And then sending that information to consciousness (which a dream is a form of). Intuition is also a way the unconscious mind communicates with consciousness. But one should bear in mind that during human evolution, the unconscious mind wasn't required to distinguish between fact and fantasy. Therefore, fantasy has just as much impact on the unconscious mind as does reality. And therefore, intuition and dreams can sometimes be misleading.

Also, some philosophers in the past have made pretty good guesses about how something in reality works. But only empirical evidence (scientific research) can tell us who made a good guess and who was wrong. So the next philosopher who insinuates that reality is only an illusion, ask the philosopher if he minds if you put an "illusory" 44 magnum against the side of his head and pull the trigger. I'll bet the act would wake the philosopher up to reality.

"Common-sense suggests at least "two orders of reality" (CEM Joad), so for Richard Dawkins to posit only one 'Science-based' reality, to explain what is real, suggests not least a lack of balance on his part" - Richard W. Symonds
(On seeing "What's real?" by Richard Dawkins - Front Page, Eureka Magazine, The Times, September 2011)